docs: def get_alternative(self, experiment_name):
          """
          Get the alternative this user is enrolled in.
          """
          experiment = None
          try:
              # catching the KeyError instead of using .get so that the experiment is auto created if desired
              experiment = experiment_manager[experiment_name]
          except KeyError:
              pass
          if experiment:
              if experiment.is_displaying_alternatives():
                  alternative = self._get_enrollment(experiment)
                  if alternative is not None:
                      return alternative
              else:
                  return experiment.default_alternative
          return conf.CONTROL_GROUP